Welcome back to Everyday Grammar from VOA Learning English.

The English language has an interesting way of classifying words. We organize words by their function or purpose. These functions are parts of speech. You might find that a noun acts like a verb, as with the word impact. Once you would talk about something having an impact. This is the noun form of impact. Now you can say you want to impact a decision process. That is the verb form of impact.

You know that an adjective modifies, describing a quality of a noun. For example, you drink a cup of hot tea. The adjective is hot and the noun is tea. What about lemon tea? Lemon is a noun, isn't it? Why is it modifying tea?

English often uses nouns as adjectives - to modify other nouns. For example, a car that people drive in races is a race car. A car with extra power or speed is a sports car. Nouns that modify other nouns are called adjectival nouns or noun modifiers. For our purposes, they are called attributive nouns. So we will use that term.

Did you notice something unusual about the expressions with the noun car? A car used to race other cars is a race car. Both nouns are singular. A car that has power and speed is a sports car. Why is the first noun, sports, plural? A search of the Internet shows us that people started using this phrase back in 1914. Cars were a new thing then.

There is no rule about whether the attributive noun is singular or plural. Most of the time it is singular. But if the combination of nouns includes a plural noun, it usually stays that way. The result is phrases like ladies room – not lady room, for a room meant for women and girls, and bean soup but not beans soup for a soup made of beans.

Some grammar experts think that English speakers are using more plural nouns in this way. We have arms race, benefits office, and women leaders. At times, a singular noun changes the meaning. An arts degree recognizes completion of a study program at a college or university in the humanities (or liberal arts). But an art degree is a degree in the fine arts.

When writing these attributive nouns in English, learners sometimes wonder about whether to use an apostrophe to show possession. Is it a ladies' room? No, it is a ladies room. Attributive nouns do not need the apostrophe. So we write Veterans Day in American English and not Veteran's Day or Veterans' Day. That means the day is in honor of military veterans, not owned by veterans.

Try to identify the attributive nouns George Harrison uses in The Beatles' song Piggies.

Everywhere there's lots of piggies
Living piggy lives
You can see them out for dinner
With their piggy wives
Clutching forks and knives
To eat their bacon

For Learning English Everyday Grammar, I'm Jill Robbins.

part of speech – grammar. a class of words (such as adjectives, adverbs, nouns and verbs) that are ordered by the kinds of ideas they express and the way they work in a sentence

impact – v. to have a strong and often bad effect on (something or someone) n. a powerful or major influence or effect

attributive – grammar. joined directly to a noun in order to describe it

modify – grammar. to limit or describe the meaning of (a word or words)

apostrophe – n. the punctuation mark ʼ used to show the possessive form of a noun or to show that letters or numbers are missing

Now it's your turn. Write a sentence that uses an attributive noun in the comments section.